Etoposide and teniposide are semi-synthetic podophyllotoxin derivatives that are in clinical usage as anticancer drugs FIG. 1 (Chen. Y. Z.; Wang. Y. G.; Tian, X.; Li, J. X. Curr. Sci 1990, 59, 517.; Wang, J. Z.; Tian, X.; Tsumura, H.; Shimura, K.; Ito, H. Anti-cancer Drug Design, 1993, 8, 193). It is believed that analogues of 4′-demethyl epipodophyllotoxin exert their antitumour activity through stabilization of a cleavable complex between DNA and type II DNA topoisomerase, this leads ultimately to inhibition of DNA catenation activity and produces single and double strand breaks (Satio, H.; Yoshikawa, H.; Nishimura, Y.; Kondo, S.; Takeuchi, T.; Umezawa, H. Chem Pharm. Bull. 1986, 34, 3733.; Chen, Y. Z.; Wang, Y. G.; Li, J. X.; Tian, X.; Jia. Z. P.; Zhang, Z. Y. Life Sci. 1989, 45, 2569) A number of studies have been carried out on the structural modification of glycoside by amino substituents that has improved the inhibitory activity on human DNA topoisomerase II as well as stronger activity in causing cellular protein length DNA breakage (Lee, K. H.; Imakura, Y.; Haruna, M.; Beers, S. A.; Thurston, L. S.; Dai, H. J.; Chen, C. H.; Liu, S. Y.; Cheng, Y. C. J. Nat. Prod. 1989, 52, 606.; Liu, S. Y.; Hawang, B. D.; Haruna, M.; Imakura, Y.; Lee, K. H.; Cheng, Y. C. Mol. Pharmcol. 1989, 36, 8.; Lee, K, H.; Beers, S. A.; Mori, M.; Wang, Z. Q.; Kuo, Y. H.; Li, L.; Liu, S. Y.; Cheng, Y. C.; J. Med. Chem. 1990, 33, 1364.; Kamal, A.; Gayatri, N. L.; Reddy, D. R.; Reddy, P. S. M. M.; Arifuddin, M.; Dastidar, S. G.; Kondapi, M. A.; Rajkumar M. Bioorg. Med. Chem. 2005, 13, 6218; Kamal, A.; Kumar, B. A.; Arifuddin, M.; Dastidar, S. G. Bioorg. Med. Chem. 2003, 11, 5135). In this context a large number of 4β-amino derivatives of podophyllotoxin and 4′-O-demethyl epipodophyllotoxin based compounds have been synthesized and investigated for their antitumour activity.
